Re: changes to the zfs boot (was: Re: git: 72a1cb05cd23 - main - rc(8): Add a zpoolupgrade rc.d script)

Quoting "Patrick M. Hausen" <pmh@hausen.com> (from Wed, 9 Nov 2022  
21:19:23 +0100):

> Hi,
>
>> Am 09.11.2022 um 21:15 schrieb Alexander Leidinger  
>> <Alexander@leidinger.net>:
>> Quoting "Patrick M. Hausen" <pmh@hausen.com> (from Wed, 9 Nov 2022  
>> 21:02:52 +0100):
>>> Yet, I made it a habit to whenever I see this message:
>>>
>>> -----------
>>> status: Some supported features are not enabled on the pool. The pool can
>>> 	still be used, but some features are unavailable.
>>> action: Enable all features using 'zpool upgrade'. Once this is done,
>>> 	the pool may no longer be accessible by software that does not support
>>> 	the features. See zpool-features(7) for details.
>>> -----------
>>>
>>> to do a "zpool upgrade" after some time of burn in followed by an  
>>> update of the
>>> boot loader.
>>>
>>> I desire to know if that is in fact dangerous.
>>
>> Ugh. This changed. It is indeed dangerous now. I just tested it  
>> with a non-root pool which didn't had all flags enabled. "zpool  
>> upgrade <pool>" will now enable all features.
>
> I know. But until now I assumed that features *enabled* but not  
> *used* were not impeding booting.
> And that for all others the boot loader was supposed to keep track.

Some features are used directly when enabled. Some features go back to  
the enabled state when some conditions are met. Some features are not  
reversible without re-creating the pool (e.g. device_removal). The  
zzpool-features man-page gives explanations which features belong into  
which category.

Bye,
Alexander.

-- 
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